Republicans are trying again today on health care. A new version of the Senate bill to repeal and replace the Affordable Care Act is supposed to be released in the coming hours, but it remains to be seen how Majority Leader Mitch McConnell can get enough Republicans on board to pass it. Let's talk about this with NPR's Scott Detrow. How are you, Scott?

SCOTT DETROW, BYLINE: Morning, David.

GREENE: I guess the question is not how are you, although I really do care. How are Republicans? How are they feeling - and any more optimism here that they can get this bill successfully voted on?

DETROW: You know, I'm doing pretty well. I think Senate Republicans will find out in a few hours because they've got a hard divide to bridge. And the divide is basically what it was a few weeks ago when this bill was stalled. They can only afford to lose two Republican votes and still pass this bill. But there's a half dozen or more Republican lawmakers who have real problems with the measure, and they're divided into two camps. You have conservative hardliners, who want to repeal as much of Obamacare as possible. And you have moderate Republicans, many representing states that did expand Medicaid, who are worried about what these cutbacks would do to people in their states who rely on Medicaid and like parts of the Affordable Care Act.

GREENE: Well, are there senators who you're watching closely and you feel like if he or she starts to come around that means something - there might be some movement here?

DETROW: Yeah, two people to keep an eye on today - Dean Heller of Nevada. He was a really forceful critic when the first Senate Republican bill was released a couple weeks ago. And that really surprised people, how far out on a ledge he went criticizing this measure, criticizing what it did for his state's budget and for Medicare in Nevada. So if he suddenly feels much better about this plan because of increased money for subsidies, for poor people being covered, for opioid treatment, that goes a long way.

Another person is Ted Cruz of Texas. He has been pushing for a proposal that may or may not end up in the plan released today - we don't know for sure just yet - that would allow insurance companies to provide scaled-back coverage - cheaper plans that don't cover as much - as long as they provide at least one plan that requires all of the Obamacare mandates. He says that would allow a lot of people to get cheaper healthcare - that is true.

But most analysts worry that if the younger, healthier people flock to those cheaper plans, that would leave a pool of people who have more expensive needs and would kind of create a cost spiral, where costs go up for the people who really do have pre-existing conditions and things that cost a lot of money to cover.

GREENE: OK, so many of the concerns - much of the criticism of the bill sounds similar to what we've heard for some time now. Let's talk timeline here. So you and I and other journalists are going to be watching senators like Dean Heller, senators like Ted Cruz. So will we know fairly quickly the chances of this bill?

DETROW: I think so. One thing to keep an eye on - early next week, probably Monday, the Congressional Budget Office will release its score of the latest version of this bill. These previous analysis have really done a lot of damage to the effort to get this bill passed. The CBO is the ones who have said - the last version of the bill - 22 million people would be without health care over the next decade. That really sunk in with the public. You see that in the poll results. So they'll weigh in on Monday or Tuesday.

And then at some point next week, there's going to be a key early test vote - a motion to proceed, it's called. If Senate Majority Leader Mitch McConnell doesn't have enough votes to proceed, that essentially kills this process. And, you know, that's the end of health care for now as it's been as a Republican-only plan.

GREENE: As a Republican-only plan, you say. So what is the plan - what is plan C for the GOP if this one does fail?

DETROW: McConnell has said a few times - he said it again last week in Kentucky during the recess - that if Republicans can't get what they want - that repeal and replace of Obamacare - he's going to turn to Democrats and work on a broader bill to deal with health care issues. That would require 60 votes. That means that moderate Democrats like Jon Tester of Montana, Heidi Heitkamp of North Dakota, they would be the key swing votes. They say they're ready to have that conversation, but they would have some hard requirements, including not scaling back Medicaid at all and leaving those mandates in place that every American needs to buy health care.

[POST-BROADCAST CORRECTION: Republican Sen. Dean Heller of Nevada has criticized the Senate health care bill's impact on Medicaid in Nevada, not Medicare as is said in this report.] Transcript provided by NPR, Copyright NPR.